In transmissions having at least one transmission stage formed by a planetary gear set, it might be conventional for stop means to be inserted between mutually adjacent transmission parts which move relative to one another at different rotational speeds, which stop means limit the axial mobility of the two transmission parts rotating differently from one another.
In particular, in the case of planetary gear sets, the drive input pinion is often not axially fixed and must therefore be limited axially in terms of its mobility by stop means. Axial forces are generated in a planet stage of a planetary gear set, and friction is generated as a result of the combination of rotational speed difference and axial forces. The stop means may serve simultaneously to protect the sun gear or sun pinion, and, perhaps, it is conventional in the prior art for hardened stop discs, hardened spherical thrust pieces, axial bearing discs, deep-groove ball bearings or thrust pieces and stop discs composed of brass or bronze to be used as stop means. In transmissions for drive systems of construction machines and mining machines, use is normally made of spherical thrust pieces, axial bearing discs and/or thrust pieces composed of brass or bronze.
A generic transmission having a plurality of transmission stages and stop discs between the sun gear and further transmission parts is known for example from DE 10 2008 050 187 A1. In the generic transmission, the stop discs can be composed of different materials such as metal, metal alloy, plastic or Teflon™ and they are produced as punched parts which extend substantially over the entire surface of the face side of the planet carrier.
The applicant has, since 1995, marketed a transmission for drive systems for underground mining applications as the “CST drive system”, which is described, for example, in DE 4316 798 Al. In said transmission, which is provided with a wet-running overload clutch, use is made, as stop means, either of thrust pieces arranged on the axis on both transmission parts and with a hardened spherical contact surface, or of annular hardened stop discs with Rockwell hardnesses of 58 to 62 HRC. The spherical thrust pieces and/or the stop discs are held in the face sides for example of the sun gear and of the planet carrier by means of special receiving elements in order to be exchangeable if necessary during maintenance of the transmission. A special receiving device which must be custom-made for every transmission type is however required. In particular owing to the increasing installed levels of drive power, the stop means are subjected to increased wear, as a result of which the operating duration of a corresponding transmission can be shortened.
The present disclosure is directed, at least in part, to improving or overcoming one or more aspects of prior systems.